Segmented worms
The worms are very beautiful. Lots of different colors. They flip into their cocoons if you get to close. But if you are patient enough, you can watch them come out again. Don’t the touch the fire worm. If the word fire is in a name (like in some fire corals) it is fire when you touch it. Waving water over the exposed area might help a bit, but mostly it takes a while for the sting to go away.